I've seen another thread about this that is tagged as "Can't be reproduced", but after spending time chasing this issue, it can be reproduced. In MP, the game will freeze anytime a player logs into the server. The duration of the freeze can be anywhere from between around 12 seconds to as long as 45 seconds. In the case where there are multiple logins at once, it can be much longer because other users think that the need to log out/in to fix it not realizing that this makes it worse which in turn prompts others to try a relog too. This is more than just lag or loss of frames, this is a complete halt of the game until that user is logged in. During this time, you can change the camera angle and toggle inventory but you can't do anything else. For example, you can be jumping and then halted in mid-air. The more popular the server is the more often it happens because more players are logging in/out. I have seen this on other servers and tested it on my own and can confirm that it happens with a dedicated server, not sure about temporary session MP though. It does not matter how long its been since a server restart and it does not matter how many people are logged in... I literally restarted my server and logged in, 5 minutes later I had someone else login and despite the restart and the fact that this was just player #2, the freeze still happened. By chance I was able to confirm this again later in the night when another player logged in right in front of me.